Package assembly for embedded die and associated techniques and configurations

ABSTRACT

Embodiments of the present disclosure are directed towards a package assembly for embedded die and associated techniques and configurations. In one embodiment, an apparatus includes a package assembly comprising a die attach layer, a die coupled with the die attach layer, the die having an active side including active devices of the die and an inactive side disposed opposite to the active side, a reinforced plate coupled with the die attach layer, the reinforced plate having a first side and a second side disposed opposite to the first side and a cavity disposed in the reinforced plate and one or more build-up layers coupled with the second side of the reinforced plate, the one or more build-up layers including an insulator and conductive features disposed in the insulator, the conductive features being electrically coupled with the die, wherein the inactive side of the die is in direct contact with the die attach layer, the first side of the reinforced plate is in direct contact with the die attach layer and the die is disposed in the cavity. Other embodiments may be described and/or claimed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 15/611,428, entitled “PACKAGE ASSEMBLY FOR EMBEDDED DIE ANDASSOCIATED TECHNIQUES AND CONFIGURATIONS”, filed Jun. 1, 2017, which isa divisional application of U.S. patent Ser. No. 13/928,179, filed Jun.26, 2013, entitled “PACKAGE ASSEMBLY FOR EMBEDDED DIE AND ASSOCIATEDTECHNIQUES AND CONFIGURATIONS,” now U.S. Pat. No. 9,685,414, and claimspriority to the Ser. Nos. 15/611,428 and 13/928,179 applications. Thedisclosures of Ser. Nos. 15/611,428 and 13/928,179 are hereby fullyincorporated by reference.

FIELD

Embodiments of the present disclosure generally relate to the field ofintegrated circuits, and more particularly, to a package assembly forembedded die and associated techniques and configurations.

BACKGROUND

Currently, integrated circuit (IC) package assemblies may includepackage-on-package (PoP) configurations where a first package substrateis coupled with a second package substrate using an interposer disposedbetween the first and second package substrate. For example, the firstpackage substrate may be a thin coreless substrate for a processor andthe second package substrate may be for a memory component and the firstand second package substrate may each be coupled with the interposerusing micro solder balls. A resulting PoP structure using the interposermay have a height (e.g., z-height) that limits implementation of the PoPstructure in small form factor devices such as, for example, mobilecomputing devices that continue to shrink to smaller dimensions.

Furthermore, the thin coreless substrate may require a fixture jig tohandle the substrate during assembly processes such as solder ballreflow, die attach, and/or interposer attach operations owing to lack ofstructural rigidity. Using the fixture jig may increase assembly costsand complexity. Additionally, in some cases, a high temperature (e.g.,−260° C.) thermal process may be used to couple the die with thesubstrate using a solderable material, which may result in thermalstress related defects (e.g., warpage) due to difference in coefficientof thermal expansion (CTE) between the die and the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. To facilitatethis description, like reference numerals designate like structuralelements. Embodiments are illustrated by way of example and not by wayof limitation in the figures of the accompanying drawings.

FIG. 1 schematically illustrates a cross-section side view of an exampleintegrated circuit (IC) package assembly, in accordance with someembodiments.

FIGS. 2a-h schematically illustrate various stages of fabrication of anexample IC package assembly, in accordance with some embodiments.

FIG. 3 schematically illustrates a cross-section side view of anotherexample IC package assembly, in accordance with some embodiments.

FIG. 4 schematically illustrates a cross-section side view of yetanother example IC package assembly, in accordance with someembodiments.

FIG. 5 schematically illustrates a cross-section side view of still yetanother example IC package assembly, in accordance with someembodiments.

FIG. 6 schematically illustrates a cross-section side view of still yetanother example IC package assembly, in accordance with someembodiments.

FIG. 7 schematically illustrates a flow diagram for a method offabricating an IC package assembly, in accordance with some embodiments.

FIG. 8 schematically illustrates a computing device that includes an ICpackage assembly as described herein, in accordance with someembodiments.

DETAILED DESCRIPTION

Embodiments of the present disclosure a package assembly for embeddeddie and associated techniques and configurations. In the followingdescription, various aspects of the illustrative implementations will bedescribed using terms commonly employed by those skilled in the art toconvey the substance of their work to others skilled in the art.However, it will be apparent to those skilled in the art thatembodiments of the present disclosure may be practiced with only some ofthe described aspects. For purposes of explanation, specific numbers,materials and configurations are set forth in order to provide athorough understanding of the illustrative implementations. However, itwill be apparent to one skilled in the art that embodiments of thepresent disclosure may be practiced without the specific details. Inother instances, well-known features are omitted or simplified in ordernot to obscure the illustrative implementations.

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, wherein like numeralsdesignate like parts throughout, and in which is shown by way ofillustration embodiments in which the subject matter of the presentdisclosure may be practiced. It is to be understood that otherembodiments may be utilized and structural or logical changes may bemade without departing from the scope of the present disclosure.Therefore, the following detailed description is not to be taken in alimiting sense, and the scope of embodiments is defined by the appendedclaims and their equivalents.

For the purposes of the present disclosure, the phrase “A and/or B”means (A), (B), or (A and B). For the purposes of the presentdisclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B),(A and C), (B and C), or (A, B and C).

The description may use perspective-based descriptions such astop/bottom, in/out, over/under, and the like. Such descriptions aremerely used to facilitate the discussion and are not intended torestrict the application of embodiments described herein to anyparticular orientation.

The description may use the phrases “in an embodiment,” or “inembodiments,” which may each refer to one or more of the same ordifferent embodiments. Furthermore, the terms “comprising,” “including,”“having,” and the like, as used with respect to embodiments of thepresent disclosure, are synonymous.

The term “coupled with,” along with its derivatives, may be used herein.“Coupled” may mean one or more of the following. “Coupled” may mean thattwo or more elements are in direct physical or electrical contact.However, “coupled” may also mean that two or more elements indirectlycontact each other, but yet still cooperate or interact with each other,and may mean that one or more other elements are coupled or connectedbetween the elements that are said to be coupled with each other. Theterm “directly coupled” may mean that two or more elements are in directcontact.

In various embodiments, the phrase “a first feature formed, deposited,or otherwise disposed on a second feature,” may mean that the firstfeature is formed, deposited, or disposed over the second feature, andat least a part of the first feature may be in direct contact (e.g.,direct physical and/or electrical contact) or indirect contact (e.g.,having one or more other features between the first feature and thesecond feature) with at least a part of the second feature.

As used herein, the term “module” may refer to, be part of, or includean Application Specific Integrated Circuit (ASIC), an electroniccircuit, a system-on-chip (SoC), a processor (shared, dedicated, orgroup) and/or memory (shared, dedicated, or group) that execute one ormore software or firmware programs, a combinational logic circuit,and/or other suitable components that provide the describedfunctionality.

FIG. 1 schematically illustrates a cross-section side view of an exampleintegrated circuit (IC) package assembly (hereinafter “package assembly100”), in accordance with some embodiments. In some embodiments, thepackage assembly 100 includes a package substrate 104 coupled with oneor more dies (e.g., dies 102 a, 102 b) and a circuit board 106, as canbe seen.

In an embodiment, the package assembly 100 may refer to only the packagesubstrate 104. The package substrate 104 may include a die attach layer108, a reinforced layer (hereinafter “reinforced plate 110”), a laminatelayer 112 and one or more build-up layers (hereinafter “build-up layers114”), coupled as shown.

The package substrate 104 may include a die attach layer 108, which maybe used as a substrate for attachment of the die 102 a. That is, in someembodiments, the die 102 a may be coupled in direct contact with the dieattach layer 108. In some embodiments, the die attach layer 108 may becomposed of an electrically insulative material such as, for example, anepoxy resin. In some embodiments, the die attach layer 108 may becomposed of a same material as an insulator 114 a of the build-up layers114. The die attach layer 108 may be composed of other suitablematerials in other embodiments.

The package assembly 100 may include a die 102 a coupled with the dieattach layer 108 and embedded in the package substrate 104. The die 102a may have an active side, A, including active devices such as, forexample, one or more transistor devices and an inactive side, I,disposed opposite to the active side A. In some embodiments, theinactive side I of the die 102 a may be in direct contact with the dieattach layer 108. The die 102 a may be a discrete unit of an IC productmade from a semiconductor material using semiconductor fabricationtechniques such as thin film deposition, lithography, etching and thelike. In some embodiments, the die may be, include, or be a part of aprocessor, memory, system on chip (SoC) or ASIC in some embodiments. Inone embodiment, the die 102 a is a processor such as, for example, acentral processing unit (CPU). The die 102 a may be configured to serveother functions in other embodiments.

The package substrate 104 may further include a reinforced plate 110coupled with the die attach layer 108. The reinforced plate 110 mayinclude a material that is reinforced relative to material of the dieattach layer 108 and/or build-up layers 114. For example, in someembodiments, material of the reinforced plate 110 may have an elasticmodulus that is greater than an elastic modulus of material of the dieattach layer 108 and/or build-up layers 114 or the reinforced plate mayhave a thickness that is greater (e.g., to provides greater structuralrigidity) than a thickness of the die attach layer 108 and/or individualor multiple layers of the build-up layers.

In some embodiments, the reinforced plate 110 may be composed of anepoxy resin with glass cloth. In other embodiments, the reinforced plate110 may be composed of a metal (e.g., as described in connection withFIG. 3). The reinforced plate 110 may be composed of other suitablematerials in other embodiments. The reinforced plate 110 may strengthenthe package substrate 104 for handling and/or assembly associated withfabrication of the build-up layers 114 using, for example bumplessbuild-up layer (BBUL) techniques. For example, in some embodiments, thereinforced plate 110 may obviate a need for using a fixture jig, whichmay be used for handling and/or assembly during fabrication of aflexible package substrate.

The reinforced plate 110 may have a first side, S1, and a second side,S2, disposed opposite to the first side S1. In some embodiments, thefirst side S1 may be in direct contact with the die attach layer 108.The reinforced plate 110 may further have a cavity 110 a formed in thereinforced plate 110. In some embodiments, the cavity 110 a may passthrough the reinforced plate 110 to provide an opening between the firstside S1 and the second side S2, as can be seen.

In some embodiments, the die 102 a may be disposed in the cavity 110 a.The die may have a thickness that is less than a thickness of thereinforced plate 110 as measured from the first side S1 to the secondside S2, as can be seen, in some embodiments. Embedding the die 102 a inthe cavity 110 a may reduce a total height (e.g., Z dimension indicatedby arrow in FIG. 1) of the package substrate 104 and/or package assembly100. For example, a separate discrete interposer element may not beneeded to couple the package substrate 104 housing the die 102 a withthe die 102 b (e.g., no need for micro-solder ball connections betweenpackages housing respective dies 102 a and 102 b), which may allowreduction of the package height.

In some embodiments, the reinforced plate 110 may include one or moreinterconnects configured to electrically couple the first side S1 andthe second side S2 of the reinforced plate 110 such as, for example,plated through holes (PTHs) 110 b. The PTHs 110 b may be configured toroute electrical signals of the die 102 a (and/or possibly other diessuch as die 102 b). In some embodiments, the PTHs 110 b may include aplated opening 110 c composed of an electrically conductive materialsuch as a metal (e.g., copper) filled with a plugging material 110 dsuch as, for example, epoxy resin. The reinforced plate 110 may includeother suitable interconnect structures formed through the reinforcedplate 110 to route the electrical signals in other embodiments.

The package substrate 104 may further include a laminate layer 112coupled with the reinforced plate 110 and disposed between the build-uplayers 114 and the reinforced plate 110. In some embodiments, thelaminate layer 112 may be in direct contact with the second side S2 ofthe reinforced plate 110. The laminate layer 112 may include prepregmaterial (e.g., B-stage material) that flows into the cavity 110 a toprovide a die encapsulant material 112 a of the die 102 a when subjectedto a thermal and/or pressure process (e.g., hot press process). The dieencapsulant material 112 a may include prepreg material disposed in thecavity 110 a and at least partially encapsulating the active side Aand/or sidewalls of the die 102 a. The die encapsulant material 112 amay fill or substantially fill the cavity 110 a in some embodiments.

In some embodiments, the prepreg material of the laminate layer 112 anddie encapsulant material 112 a may include an epoxy resin with glasscloth. The prepreg material may further strengthen and/or reinforce thepackage substrate 104 for handling and/or assembly associated withfabrication of the build-up layers 114. The material of the laminatelayer 112 and die encapsulant material 112 a may include other suitablematerials in other embodiments.

One or more interconnects may be formed in the laminate layer 112 toelectrically couple the die 102 a with conductive features 114 b (e.g.,electrical routing features) of the build-up layers 114. For example, insome embodiments, the interconnects may include via structures 112 bthat extend through the laminate layer 112 and die encapsulant material112 a to corresponding contacts such as pads on the die 102 a. The viastructures 112 b may be formed using any suitable process including, forexample, a laser process to remove material of the laminate layer 112and die encapsulant material 112 a to provide a laser via joint betweenthe die 102 a and the build-up layers 114. The laser via joint may havea structure consistent with being formed by a laser process. Forexample, a profile of the laser via joint may taper as can be seen. Theinterconnects of the laminate layer 112 may include other suitableinterconnect structures in other embodiments.

Using a laser process to form openings in the laminate layer 112 and/ordie encapsulate material 112 a may be performed at a temperature (e.g.,at or near room temperature) that is much lower than a solder reflowtemperature. Accordingly, using a laser process to fabricate the laservia joint for first-level interconnect (FLI) between the die 102 a andthe package substrate 104 may reduce or eliminate thermal relateddefects (e.g., stress or warpage) that may cause interconnectreliability failures or other FLI defects associated with CTE mismatchbetween the die 102 a and the package substrate 104. For example,defects such as massive solder bump-bridge (MSBB), die misalignment (DM)and non-contact open (NCO) defects associated with using micro-ballinterconnects may be reduced and/or eliminated in the package assembly100.

The package substrate 104 may further include the build-up layers 114coupled with the first side of reinforced plate 110. In someembodiments, an individual build-up layer of the build-up layers 114 isin direct contact with the laminate layer 112. The build-up layers 114may include electrical routing features (e.g., hereinafter “conductivefeatures 114 b”) of individual build-up layers 114 coupled together inan electrically insulative material (hereinafter “insulator 114 a”). Theconductive features 114 b may include, for example, trenches, vias,traces or other suitable routing structures composed of an electricallyconductive material such as metal (e.g., copper). The insulator 114 amay be composed of an epoxy resin. The conductive features 114 b and theinsulator 114 a may be composed of other suitable materials in otherembodiments. In some embodiments, the build-up layers 114 may be formedusing Ajinomoto Build-up Film (ABF) techniques. Other suitabletechniques to fabricate the build-up layers 114 may be used in otherembodiments.

In some embodiments, another die 102 b may be coupled with the packagesubstrate 104. For example, in the depicted embodiment, the die 102 b iscoupled with the build-up layers 114 in a flip-chip configuration usingsolderable material 116 such as solder bumps to couple correspondingcontacts (e.g., pads) on the die 102 b with the conductive features 114b of the build-up layers 114. In some embodiments, an underfill material118 may be disposed between an active side of the die 102 b and thepackage substrate 104. The die 102 b may be coupled with the packagesubstrate 104 using other suitable techniques such as, for example,wirebonding techniques, embedding techniques and the like or other FLIinterconnect structures such as pillars to couple the die 102 b with thepackage substrate 104.

According to various embodiments, the first die 102 a may be a logic diesuch as, for example, a processor or ASIC and the second die 102 b maybe a memory die. The first dies 102 a and/or 102 b may be configured toperform other functions in other embodiments.

In some embodiments, the conductive features 114 b of the build-uplayers 114 may be electrically coupled with the dies 102 a and/or 102 b(e.g., and possibly other dies) and configured to route electricalsignals of the dies 102 a and/or 102 b through the package substrate104. The electrical signals may include, for example, input/output (I/Osignals) and/or power/ground signals associated with operation of thedies 102 a, 102 b. In some embodiments, the conductive features 114 bmay route electrical signals between the dies 102 a, 102 b. In thisregard, the dies 102 a and 102 b may be electrically coupled with oneanother. In some embodiments, the conductive features 114 b may routeelectrical signals between one or more of the dies 102 a, 102 b andanother electrical component such as, for example, a circuit board 106by way of interconnects in the laminate layer 112, PTHs 110 b and/orpackage-level interconnects such as solder balls 120.

In some embodiments, one or more package-level interconnects such as,for example, solder balls 120 may be coupled with the package substrate104 to further route the electrical signals to another electricalcomponent such as circuit board 106. The solder balls 120 may bearranged in a ball-grid array (BGA) configuration in some embodiments.The package-level interconnects may include other suitable structuressuch as, for example, land-grid array (LGA) structures. Thepackage-level interconnects (e.g., solder balls 120) may be coupled withthe PTHs 110 b through the die attach layer 108, as can be seen, in someembodiments. In other embodiments, additional build-up layers (notshown) may be formed on the die attach layer 108 to provide additionalelectrical routing for the package substrate 104 and the package-levelinterconnects may be coupled with the additional build-up layers.

The package assembly 100 may further include a circuit board 106 coupledwith the package substrate 104 through the package-level interconnects(e.g., solder balls 120). Only a small portion of the circuit board 106may be depicted for the sake of discussion. The package-levelinterconnects may be coupled with contacts (e.g., pads) of the circuitboard 106 to route electrical signals of the dies 102 a, 102 b betweenthe package substrate 104 and the circuit board 106. The circuit board106 may be a printed circuit board (PCB) composed of an electricallyinsulative material such as, for example, an epoxy laminate. Forexample, the circuit board 106 may include electrically insulatinglayers composed of materials such as, for example,polytetrafluoroethylene, phenolic cotton paper materials such as FlameRetardant 4 (FR-4), FR-1, cotton paper and epoxy materials such as CEM-1or CEM-3, or woven glass materials that are laminated together using anepoxy resin prepreg material. Electrical routing structures (not shown)such as traces, trenches, vias, and the like may be formed through theelectrically insulating layers to route the electrical signals of thedies 102 a, 102 b through the circuit board 106. The circuit board 106may be composed of other suitable materials in other embodiments. Insome embodiments, the circuit board 106 is a motherboard (e.g.,motherboard 802 of FIG. 8).

The package assembly 100 may include components configured in a widevariety of other suitable configurations in other embodiments including,for example, interposers, multi-chip package configurations includingsystem-in-package (SiP) and/or package-on-package (PoP) configurationsto route electrical signals between the dies 102 a, 102 b and otherelectrical components in some embodiments.

FIGS. 2a-h schematically illustrate various stages of fabrication of anexample IC package assembly (hereinafter “package assembly 200”), inaccordance with some embodiments. The package assembly 200 may comportwith embodiments described in connection with package assembly 100 andvice versa.

FIG. 2a depicts the package assembly 200 subsequent to providing a dieattach layer 108 on a dummy panel (hereinafter “panel 224”), which mayfacilitate handling of the package assembly 200 during fabrication. Apeelable core 222, which may be composed of a metal such as, forexample, copper, may be disposed on the panel 224 to receive and holdthe die attach layer 108. In some embodiments, the die attach layer 108may include a B-stage resin that is placed on the peelable core 222.

A die 102 a and reinforced plate 110 may be placed on the die attachlayer 108 as indicated by the downward arrows. Prior to placement on thedie attach layer 108, the reinforced plate 110 may be fabricated toinclude one or more PTHs 110 b having a cavity 110 a and traces 110 eformed on both sides of plated openings 110 c that may be filled with aplugging material 110 d.

FIG. 2b depicts the package assembly 200 subsequent to coupling the die102 a and the reinforced plate 110 with the die attach layer 108. Thedie 102 a and the reinforced plate 110 may be coupled with the dieattach layer 108 using any suitable technique. In some embodiments, alamination process may be used to couple the die 102 a and thereinforced plate 110 with the die attach layer 108. For example, a hotpressing process in a vacuum environment may be used to apply heat andpressure between the die attach layer 108 and the reinforced plate 110and/or between the die attach layer 108 and the die 102 a. In someembodiments, the hot pressing may be followed by a curing process, whichmay be used to cure the B-stage resin of the die attach layer 108. Insome embodiments, the die 102 a and the reinforced plate 110 may becoupled with the die attach layer 108 simultaneously (e.g., using a samehot press process and/or curing process).

FIG. 2c depicts the package assembly 200 subsequent to providing alaminate layer 112 for placement on the reinforced plate 110 and FIG. 2ddepicts the package assembly 200 subsequent to performing a laminationprocess to couple the laminate layer 112 with the reinforced plate 110and to fill the cavity 110 a with material of the laminate layer 112 toprovide die encapsulant material 112 a. The laminate layer 112 may becomposed of a B-stage prepreg material in some embodiments. In someembodiments, the lamination process includes a hot press process. Othersuitable techniques and/or materials may be used in connection with thelaminate layer 112 in other embodiments.

FIG. 2e depicts the package assembly 200 subsequent to forming one ormore build-up layers 114 on the laminate layer 112 and decoupling thedie attach layer 108 from the panel 224. The build-up layers 114 may beformed using any suitable technique including, for example, laminateprocesses such as ABF techniques. The peelable core 222 may be removed(e.g., by peeling) from the panel 224. The peelable core 222 may furtherbe removed from the die attach 108 by peeling and/or by etchingprocesses that are selective to removing material of the peelable core222 relative to the die attach layer 108.

In some embodiments, prior to forming the build-up layers 114, viastructures 112 b may be formed through material of the laminate layer112 to provide FLIs for the die 102 a. The via structures 112 b may beformed using a laser process to remove the material of the laminatelayer 112 in some embodiments. The laser process may include a drillingprocess that is performed using an ambient temperature that is at oraround room temperature or less than 100° C.

FIG. 2f depicts the package assembly 200 subsequent to forming openings114 c to expose conductive features 114 b of the build-up layers 114 andforming openings 108 a to expose interconnects (e.g., PTHs 110 b) of thereinforced plate 110. The openings 114 c and 108 a may be formed usingany suitable technique including, for example, a laser process to drillaway material of the insulator 114 a and/or die attach layer 108. Adesmesar process may be used to clean surfaces within the openings 114 cand/or 108 a and a surface finish may be deposited on electricallyconductive surfaces in the openings 114 c and/or 108 a to facilitateformation of joints with the electrically conductive surfaces.

FIG. 2g depicts the package assembly 200 subsequent to depositingsolderable material 116 into the openings 114 c using any suitabletechnique. The solderable material 116 may include, for example, solderbumps for die attachment. In other embodiments, the solderable material116 may be deposited on a surface of the die to be attached to thepackage assembly 200.

FIG. 2h depicts the package assembly 200 subsequent to attaching the die102 b to the package assembly 200. For example, the die 102 b may becoupled with the conductive features 114 b of the build-up layers 114using a flip-chip solder reflow process. In some embodiments, underfillmaterial 118 may be deposited in a region between the die 102 b and thepackage substrate 104.

FIG. 3 schematically illustrates a cross-section side view of anotherexample IC package assembly (hereinafter “package assembly 300”), inaccordance with some embodiments. The package assembly 300 may comportwith embodiments described in connection with package assembly 100 or200, except that the reinforced plate 110 of the package assembly 300 ofFIG. 3 includes an electrically conductive core 110 f such as a metal(e.g., aluminum or copper) and an electrically insulative layer 110 gdisposed on the core 110 f to provide a barrier between material of thecore 110 f and interconnects (e.g., PTHs 110 b) that are disposed in thereinforced plate 110 to prevent shorts and/or leakage. The core 110 fmay include a material that reduces CTE mismatch between materials(e.g., materials of the die 102 a) of the package assembly 300 duringthermal processes and/or a material that has higher thermal conductivityto facilitate heat removal away from the die 102 a.

The package assembly 300 may further include a solder resist layer 330formed on the build-up layers 114 and the die 102 b may be coupled withthe conductive features 114 b of the build-up layers 114 through thesolder resist layer 330. Although not shown, a solder resist layer 330may be formed on the die attach layer 108 in some embodiments.

FIG. 4 schematically illustrates a cross-section side view of yetanother example IC package assembly (hereinafter “package assembly400”), in accordance with some embodiments. In some embodiments, the die102 b may be coupled with an inactive side I of the die 102 a, as can beseen. In the depicted embodiment, the die 102 b is coupled with the die102 a using solderable material 116 (e.g., or other suitable FLIs) thatextends through the die attach layer 108. In some embodiments, the die102 a includes one or more through-silicon vias (TSVs) 440 disposedbetween the active side A and the inactive side I to route electricalsignals through the die 102 a. The interconnects (e.g., solderablematerial 116) of the die 102 b may be electrically coupled with the TSVs440. In some embodiments, electrical signals between the dies 102 a and102 b may be routed over the TSVs 440.

FIG. 5 schematically illustrates a cross-section side view of still yetanother example IC package assembly (hereinafter “package assembly500”), in accordance with some embodiments. The package assembly 500depicts an example PoP configuration.

In the package assembly 500, a package substrate 555 including a die 102c is coupled with the package substrate 104 of package assembly 300using package-level interconnects such as, for example, solder balls120. In the depicted embodiment, the package substrate 555 includes die102 c mounted on a laminate 552 using, for example, an adhesive such asunderfill material 118. In the depicted embodiment, the die 102 c iscoupled with the laminate 552 in a wirebonding configuration using oneor more bonding wires 556. The die 102 b is disposed between the packagesubstrate 555 and the package substrate 104.

The package substrate 555 may include electrical routing features suchas, for example, PTHs 110 b coupled with the die 102 c through thebonding wires 556. The electrical routing features of the packagesubstrate 555 may route electrical signals of the die 102 c to or frompackage-level interconnects such as solder balls 120. Other suitabletechniques to couple the die 102 c with the package substrate 555 can beused in other embodiments including, for example, flip-chipconfigurations, embedding techniques, etc.

A solder resist layer 330 may be formed on opposing sides of thelaminate 552. In some embodiments, a molding compound 554 may be formedto encapsulate the die 102 c. According to various embodiments, theunderfill material 118, the molding compound 554 and/or the solderresist layer 330 may be composed of an epoxy resin and the laminate 552may be a copper clad laminate (CCL) composed of an epoxy resin withglass cloth. Other suitable materials may be used in other embodiments.The package substrate 555 may include a wide variety of other suitableconfigurations in other embodiments. In some embodiments, the packagesubstrate 555 may include any suitable electrical routing features tocouple die 102 c with electrical routing features of the packagesubstrate 104.

FIG. 6 schematically illustrates a cross-section side view of still yetanother example IC package assembly (hereinafter “package assembly600”), in accordance with some embodiments. The package assembly 600depicts another PoP assembly. In the package assembly 600, a packagesubstrate 555 including a die 102 c is coupled with the packagesubstrate 104 of package assembly 400 using package-level interconnectssuch as, for example, solder balls 120. The die 102 c of packageassembly 500 or 600 may configured to communicate with the dies 102 aand/or 102 b and/or a circuit board through the package-levelinterconnects (e.g., solder balls 120) that couple the package substrate555 with package substrate 104.

FIG. 7 schematically illustrates a flow diagram for a method 700 offabricating an IC package assembly, in accordance with some embodiments.The method 700 may comport with techniques and/or configurationsdescribed in connection with FIGS. 1-6 and vice versa.

At 702, the method 700 may include providing a die attach layer (e.g.,die attach layer 108 of FIG. 2a ). At 704, the method 700 may includecoupling a first die (e.g., die 102 a of FIG. 2b ) with the die attachlayer. At 706, the method 700 may include coupling a reinforced plate(e.g., reinforced plate 110 of FIG. 2b ) with the die attach layer, thereinforced plate having a cavity. According to various embodiments,actions at 704 and 706 may be simultaneously performed during a sameoperation (e.g., hot pressing and/or curing process).

At 708, the method 700 may include depositing a die encapsulant material(e.g., die encapsulant material 112 a of FIG. 2d ) in the cavity. Insome embodiments, depositing the die encapsulant material in the cavitymay be performed by applying a laminate layer (e.g., laminate layer 112of FIG. 2c ) on the reinforced plate and hot pressing the laminate layerto couple the laminate layer with the reinforced plate and substantiallyfill the cavity with material of the laminate layer.

At 710, the method 700 may include forming die-level interconnects(e.g., FLIs) that extend through the die encapsulant material to thefirst die. The die-level interconnects may include, for example, viastructures (e.g., via structures 112 b of FIG. 2e ) formed using a laserdrilling technique. The die-level interconnects may include othersuitable structures in other embodiments.

At 712, the method 700 may include forming one or more build-up layers(e.g., build-up layers 114 of FIG. 2e ) of a first package substrate(e.g., package substrate 104 of FIG. 2e ) on the reinforced plate. Insome embodiments, the first die is electrically coupled with electricalrouting features (e.g., conductive features 114 b of FIG. 2e ) of theone or more build-up layers through the die-level interconnectssubsequent to forming the one or more build-up layers.

At 714, the method 700 may include electrically coupling a second die(e.g., die 102 b of FIG. 2h ) with the first die. In some embodiments,the second die is electrically coupled with the first die through theelectrical routing features of the one or more build-up layers (e.g.,package assembly 300 of FIG. 3). In other embodiments, the second die iscoupled with an inactive side of the first die (e.g., package assembly400 of FIG. 4). For example, the first die may include TSVs and thesecond die may be electrically coupled with the TSVs through theinactive side of the first die using interconnects that extend throughthe die attach layer.

At 716, the method 700 may include electrically coupling a secondpackage substrate (e.g., package substrate 555 of FIGS. 5-6) including athird die (e.g., die 102 c of FIGS. 5-6) with the first packagesubstrate (e.g., package substrate 104 of FIGS. 5-6). The second packagesubstrate may be coupled with either one of two opposing sides of thefirst package substrate as depicted, for example, in connection withFIGS. 5-6 using package-level interconnects such as solder balls 120.

At 718, the method 700 may include electrically coupling the firstpackage substrate with a circuit board (e.g., circuit board 106 of FIG.1). In some embodiments, package-level interconnects such as solderballs may be coupled with either one of the two opposing sides of thefirst package substrate to route electrical signals between the dies(e.g., first die and second die) of the first package substrate and thecircuit board. In embodiments where the second package substrate iscoupled with the first package substrate, the package-levelinterconnects formed at 718 may be further configured to routeelectrical signals between dies (e.g., third die) of the second packagesubstrate and the circuit board.

Various operations are described as multiple discrete operations inturn, in a manner that is most helpful in understanding the claimedsubject matter. However, the order of description should not beconstrued as to imply that these operations are necessarily orderdependent. For example, actions of the method 700 may be performed inanother suitable order than depicted.

Embodiments of the present disclosure may be implemented into a systemusing any suitable hardware and/or software to configure as desired FIG.8 schematically illustrates a computing device 800 that includes an ICpackage assembly as described herein, in accordance with someembodiments. The computing device 800 may house a board such asmotherboard 802. The motherboard 802 may include a number of components,including but not limited to a processor 804 and at least onecommunication chip 806. The processor 804 may be physically andelectrically coupled to the motherboard 802. In some implementations,the at least one communication chip 806 may also be physically andelectrically coupled to the motherboard 802. In further implementations,the communication chip 806 may be part of the processor 804.

Depending on its applications, computing device 800 may include othercomponents that may or may not be physically and electrically coupled tothe motherboard 802. These other components may include, but are notlimited to, volatile memory (e.g., DRAM), non-volatile memory (e.g.,ROM), flash memory, a graphics processor, a digital signal processor, acrypto processor, a chipset, an antenna, a display, a touchscreendisplay, a touchscreen controller, a battery, an audio codec, a videocodec, a power amplifier, a global positioning system (GPS) device, acompass, a Geiger counter, an accelerometer, a gyroscope, a speaker, acamera, and a mass storage device (such as hard disk drive, compact disk(CD), digital versatile disk (DVD), and so forth).

The communication chip 806 may enable wireless communications for thetransfer of data to and from the computing device 800. The term“wireless” and its derivatives may be used to describe circuits,devices, systems, methods, techniques, communications channels, etc.,that may communicate data through the use of modulated electromagneticradiation through a non-solid medium. The term does not imply that theassociated devices do not contain any wires, although in someembodiments they might not. The communication chip 806 may implement anyof a number of wireless standards or protocols, including but notlimited to Institute for Electrical and Electronic Engineers (IEEE)standards including Wi-Fi (IEEE 802.11 family), IEEE 802.16 standards(e.g., IEEE 802.16-2005 Amendment), Long-Term Evolution (LTE) projectalong with any amendments, updates, and/or revisions (e.g., advanced LTEproject, ultra mobile broadband (UMB) project (also referred to as“3GPP2”), etc.). IEEE 802.16 compatible BWA networks are generallyreferred to as WiMAX networks, an acronym that stands for WorldwideInteroperability for Microwave Access, which is a certification mark forproducts that pass conformity and interoperability tests for the IEEE802.16 standards. The communication chip 806 may operate in accordancewith a Global System for Mobile Communication (GSM), General PacketRadio Service (GPRS), Universal Mobile Telecommunications System (UMTS),High Speed Packet Access (HSPA), Evolved HSPA (E-HSPA), or LTE network.The communication chip 806 may operate in accordance with Enhanced Datafor GSM Evolution (EDGE), GSM EDGE Radio Access Network (GERAN),Universal Terrestrial Radio Access Network (UTRAN), or Evolved UTRAN(E-UTRAN). The communication chip 806 may operate in accordance withCode Division Multiple Access (CDMA), Time Division Multiple Access(TDMA), Digital Enhanced Cordless Telecommunications (DECT),Evolution-Data Optimized (EV-DO), derivatives thereof, as well as anyother wireless protocols that are designated as 3G, 4G, 5G, and beyond.The communication chip 806 may operate in accordance with other wirelessprotocols in other embodiments.

The computing device 800 may include a plurality of communication chips806. For instance, a first communication chip 806 may be dedicated toshorter range wireless communications such as Wi-Fi and Bluetooth and asecond communication chip 806 may be dedicated to longer range wirelesscommunications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, andothers.

The processor 804 of the computing device 800 may be packaged in an ICassembly (e.g., package assembly 100 of FIG. 1) as described herein. Forexample, referring to FIGS. 1 and 8, the circuit board 106 of FIG. 1 maybe a motherboard 802 and the processor 804 may be a die 102 a or 102 bpackaged in a package substrate 104. The package substrate 104 and themotherboard 802 may be coupled together using package-level interconnectstructures (e.g., solder balls 120). The term “processor” may refer toany device or portion of a device that processes electronic data fromregisters and/or memory to transform that electronic data into otherelectronic data that may be stored in registers and/or memory.

The communication chip 806 may also include a die (e.g., die 102 a or102 b of FIG. 1) that may be packaged in an IC assembly (e.g., packageassembly 100 of FIG. 1) as described herein. In further implementations,another component (e.g., memory device or other integrated circuitdevice) housed within the computing device 800 may include a die (e.g.,die 102 a or 102 b of FIG. 1) that may be packaged in an IC assembly(e.g., package assembly 100 of FIG. 1) as described herein.

In various implementations, the computing device 800 may be a laptop, anetbook, a notebook, an ultrabook, a smartphone, a tablet, a personaldigital assistant (PDA), an ultra mobile PC, a mobile phone, a desktopcomputer, a server, a printer, a scanner, a monitor, a set-top box, anentertainment control unit, a digital camera, a portable music player,or a digital video recorder. In an embodiment, the computing device 800may be a mobile computing device. In further implementations, thecomputing device 800 may be any other electronic device that processesdata.

EXAMPLES

According to various embodiments, the present disclosure describes anapparatus (e.g., package assembly) comprising a die attach layer, a diecoupled with the die attach layer, the die having an active sideincluding active devices of the die and an inactive side disposedopposite to the active side, a reinforced plate coupled with the dieattach layer, the reinforced plate having a first side and a second sidedisposed opposite to the first side and a cavity disposed in thereinforced plate and one or more build-up layers coupled with the secondside of the reinforced plate, the one or more build-up layers includingan insulator and conductive features disposed in the insulator, theconductive features being electrically coupled with the die, wherein theinactive side of the die is in direct contact with the die attach layer,the first side of the reinforced plate is in direct contact with the dieattach layer and the die is disposed in the cavity. In some embodiments,the apparatus may further include a die encapsulant material disposed inthe cavity and at least partially encapsulating the active side of thedie, wherein the die is electrically coupled with the electrical routingfeatures of the one or more build-up layers through via structures thatextend through the die encapsulant material. In some embodiments, thedie encapsulant material includes prepreg material of a laminate layerdisposed between the one or more build-up layers and the reinforcedplate, the laminate layer being in direct contact with the second sideof the reinforced plate and the die has a thickness that is less than athickness of the reinforced plate as measured from the first side to thesecond side of the reinforced plate.

In some embodiments, the die is a first die, and the apparatus furtherinclude a second die electrically coupled with the first die. In someembodiments, the second die is electrically coupled with the first diethrough the electrical routing features of the one or more build-uplayers and the reinforced plate includes plated through holes (PTHs)configured to route electrical signals of the first die and the seconddie to package-level interconnects coupled with the PTHs through the dieattach layer. In some embodiments, the one or more build-up layers, thereinforced plate and the die attach layer are part of a first packagesubstrate and the package-level interconnects are first package-levelinterconnects configured to couple the first package substrate with acircuit board. In some embodiments, the apparatus further includes asecond package substrate coupled with the first package substrate usingsecond package-level interconnects and a third die mounted on orembedded in the second package substrate, the third die beingelectrically coupled with first package substrate through the secondpackage-level interconnects, wherein the second die is disposed betweenthe first package substrate and the second package substrate.

In some embodiments, the first die includes through silicon vias (TSVs)disposed between the active side and the inactive side of the first dieand the second die is electrically coupled with the TSVs through theinactive side of the first die using interconnects that extend throughthe die attach layer. In some embodiments, the one or more build-uplayers, the reinforced plate and the die attach layer are part of afirst package substrate and the apparatus further includes first packagepackage-level interconnects configured to couple the first packagesubstrate with a circuit board a second package substrate coupled withthe first package substrate using second package-level interconnectsthat are configured to route electrical signals between the firstpackage substrate and the second package substrate through the dieattach layer and a third die mounted on or embedded in the secondpackage substrate, the third die being electrically coupled with firstpackage substrate through the second package-level interconnects. Insome embodiments, the one or more build-up layers are composed of anepoxy material and the reinforced plate is composed of an epoxy materialwith glass cloth. In some embodiments, the reinforced plate includesinterconnects configured to electrically couple the first side and thesecond side of the reinforced plate and the reinforced plate is composedof a metal core with an electrically insulative layer disposed on themetal core to electrically insulate the metal core from theinterconnects of the reinforced plate.

According to various embodiments, the present disclosure describes amethod of fabricating a package assembly, the method including providinga die attach layer, coupling a die with the die attach layer, the diehaving an active side including active devices of the die and aninactive side disposed opposite to the active side, coupling areinforced plate with the die attach layer, the reinforced plate havinga first side and a second side disposed opposite to the first side and acavity disposed in the reinforced plate and forming one or more build-uplayers on the second side of the reinforced plate, the one or morebuild-up layers including an insulator and conductive features disposedin the insulator, the conductive features being electrically coupledwith the die, wherein the inactive side of the die is in direct contactwith the die attach layer, the first side of the reinforced plate is indirect contact with the die attach layer and the die is disposed in thecavity. In some embodiments, the method further includes, prior toforming the one or more build-up layers, depositing a die encapsulantmaterial in the cavity and at least partially encapsulating the activeside of the die and forming via structures that extend through the dieencapsulant material using a laser drilling process, wherein the die iselectrically coupled with the electrical routing features of the one ormore build-up layers through the via structures subsequent to formingthe one or more build-up layers. In some embodiments, depositing the dieencapsulant material comprises applying a laminate layer on the secondside of the reinforced plate and hot pressing the laminate layer tocouple the laminate layer with the reinforced plate and substantiallyfill the cavity with prepreg material of the laminate layer.

In some embodiments, the die is a first die and the method furtherincludes electrically coupling a second die with the first die. In someembodiments, electrically coupling the second die with the first diecomprises electrically coupling the second die with the first diethrough the electrical routing features of the one or more build-uplayers. In some embodiments, the method further includes formingpackage-level interconnects that are electrically coupled with the firstdie and the second die through the die attach layer and through platedthrough holes (PTHs) disposed in the reinforced plate, the PTHsconfigured to route electrical signals of the first die and the seconddie to the package-level interconnects. In some embodiments, the one ormore build-up layers, the reinforced plate and the die attach layer arepart of a first package substrate and the package-level interconnectsare first package-level interconnects configured to couple the firstpackage substrate with a circuit board. In some embodiments, the methodfurther includes coupling a second package substrate with the firstpackage substrate using second package-level interconnects, the secondpackage substrate including a third die mounted on or embedded in thesecond package substrate, the third die being electrically coupled withfirst package substrate through the second package-level interconnects,wherein the second die is disposed between the first package substrateand the second package substrate.

In some embodiments, the first die includes through silicon vias (TSVs)disposed between the active side and the inactive side of the first die.In some embodiments, electrically coupling the second die with the firstdie comprises electrically coupling the second die with the TSVs throughthe inactive side of the first die using interconnects that extendthrough the die attach layer. In some embodiments, the one or morebuild-up layers, the reinforced plate and the die attach layer are partof a first package substrate. In some embodiments, the method furtherincludes forming first package package-level interconnects that areconfigured to couple the first package substrate with a circuit boardand coupling a second package substrate with the first package substrateusing second package-level interconnects that are configured to routeelectrical signals between the first package substrate and the secondpackage substrate through the die attach layer, the second packagesubstrate including a third die mounted on or embedded in the secondpackage substrate, the third die being electrically coupled with firstpackage substrate through the second package-level interconnects. Insome embodiments, providing a die attach layer comprises providing aB-stage resin on a panel and coupling a die with the die attach layerand coupling a reinforced plate with the die attach layer aresimultaneously performed using a hot press process to attach the die andreinforced plate with the B-stage resin.

According to various embodiments, the present disclosure describes asystem (e.g., a computing device) including a circuit board and apackage assembly coupled with the circuit board, the package assemblycomprising a die attach layer, a die coupled with the die attach layer,the die having an active side including active devices of the die and aninactive side disposed opposite to the active side, a reinforced platecoupled with the die attach layer, the reinforced plate having a firstside and a second side disposed opposite to the first side and a cavitydisposed in the reinforced plate and one or more build-up layers coupledwith the second side of the reinforced plate, the one or more build-uplayers including an insulator and conductive features disposed in theinsulator, the conductive features being electrically coupled with thedie, wherein the inactive side of the die is in direct contact with thedie attach layer, the first side of the reinforced plate is in directcontact with the die attach layer and the die is disposed in the cavity.In some embodiments, the circuit board is coupled with the packageassembly using package-level interconnects that extend through the dieattach layer. In some embodiments, the system is a mobile computingdevice further comprising one or more of an antenna, a display, atouchscreen display, a touchscreen controller, a battery, an audiocodec, a video codec, a power amplifier, a global positioning system(GPS) device, a compass, a Geiger counter, an accelerometer, agyroscope, a speaker, or a camera coupled with the circuit board.

Various embodiments may include any suitable combination of theabove-described embodiments including alternative (or) embodiments ofembodiments that are described in conjunctive form (and) above (e.g.,the “and” may be “and/or”). Furthermore, some embodiments may includeone or more articles of manufacture (e.g., non-transitorycomputer-readable media) having instructions, stored thereon, that whenexecuted result in actions of any of the above-described embodiments.Moreover, some embodiments may include apparatuses or systems having anysuitable means for carrying out the various operations of theabove-described embodiments.

The above description of illustrated implementations, including what isdescribed in the Abstract, is not intended to be exhaustive or to limitthe embodiments of the present disclosure to the precise formsdisclosed. While specific implementations and examples are describedherein for illustrative purposes, various equivalent modifications arepossible within the scope of the present disclosure, as those skilled inthe relevant art will recognize.

These modifications may be made to embodiments of the present disclosurein light of the above detailed description. The terms used in thefollowing claims should not be construed to limit various embodiments ofthe present disclosure to the specific implementations disclosed in thespecification and the claims. Rather, the scope is to be determinedentirely by the following claims, which are to be construed inaccordance with established doctrines of claim interpretation.

What is claimed is:
 1. A package assembly comprising: a die attach layerhaving a first side and a second side, wherein the die attach layer isan electrically insulative material; a first die coupled with the dieattach layer, the first die having an active side including activedevices of the first die and an inactive side opposite to the activeside, the inactive side of the first die coupled to the first side ofthe die attach layer, wherein the die attach layer is used as asubstrate for attachment of the first die; a reinforced plate coupledwith the die attach layer, the reinforced plate having a first side anda second side opposite to the first side and a cavity in the reinforcedplate, the first side of the reinforced plate coupled with the firstside of the die attach layer and the first die is in the cavity; one ormore build-up layers coupled with the second side of the reinforcedplate, the one or more build-up layers including an insulator andconductive features in the insulator, the conductive features beingelectrically coupled with the first die without wire bonds; and a seconddie electrically coupled with the first die, wherein the first die andthe second die are on a same side of the one or more build-up layers. 2.The package assembly of claim 1, wherein the second die is coupled withthe inactive side of the first die.
 3. The package assembly of claim 2,wherein the die attach layer has a plurality of openings, and the seconddie is electrically coupled with the inactive side of the first die witha plurality of interconnects that extend through the plurality ofopenings in the die attach layer.
 4. The package assembly of claim 2,wherein the first die includes one or more through-silicon vias betweenthe active side and the inactive side of the first die.
 5. The packageassembly of claim 4, wherein the second die is electrically coupled withthe inactive side of the first die with a plurality of interconnects,and wherein one or more of the plurality of interconnects areelectrically coupled with one or more of the one or more through-siliconvias.
 6. The package assembly of claim 1, wherein the reinforced plateincludes interconnects to electrically couple the first side and thesecond side of the reinforced plate.
 7. The package assembly of claim 1,wherein the one or more build-up layers cover all of the second side ofthe reinforced plate.
 8. The package assembly of claim 7, wherein thereinforced plate includes an electrically conductive core.
 9. Thepackage assembly of claim 1, wherein the die is an integrated circuitdie.
 10. The package assembly of claim 1, further comprising a solderresist layer on the one or more build-up layers, wherein the solderresist layer has openings to expose one or more of the conductivefeatures in the insulator to couple with one or more package-levelinterconnects.
 11. The package assembly of claim 1, further comprising:a die encapsulant material in the cavity and at least partiallyencapsulating the active side of the first die, wherein the first die iselectrically coupled with electrical routing features of the one or morebuild-up layers through via structures that extend through the dieencapsulant material.
 12. The package assembly of claim 1, wherein thedie attach layer is a non-composite layer.
 13. A computing devicecomprising: a circuit board; and a package assembly coupled with thecircuit board, the package assembly comprising: a die attach layerhaving a first side and a second side, wherein the die attach layer isan electrically insulative material; a first die coupled with the dieattach layer, the first die having an active side including activedevices of the first die and an inactive side opposite to the activeside, the inactive side of the first die coupled to the first side ofthe die attach layer, wherein the die attach layer is used as asubstrate for attachment of the first die; a reinforced plate coupledwith the die attach layer, the reinforced plate having a first side anda second side opposite to the first side and a cavity in the reinforcedplate, the first side of the reinforced plate coupled with the firstside of the die attach layer and the first die is in the cavity; one ormore build-up layers coupled with the second side of the reinforcedplate, the one or more build-up layers including an insulator andconductive features in the insulator, the conductive features beingelectrically coupled with the first die without wire bonds; and a seconddie electrically coupled with the first die, wherein the first die andthe second die are on a same side of the one or more build-up layers.14. The computing device of claim 13, wherein the second die is coupledwith the inactive side of the first die.
 15. The computing device ofclaim 14, wherein the die attach layer has a plurality of openings, andthe second die is electrically coupled with the inactive side of thefirst die with a plurality of interconnects that extend through theplurality of openings in the die attach layer.
 16. The computing deviceof claim 14, wherein the first die includes one or more through-siliconvias between the active side and the inactive side of the first die. 17.The computing device of claim 16, wherein the second die is electricallycoupled with the inactive side of the first die with a plurality ofinterconnects, and wherein one or more of the plurality of interconnectsare electrically coupled with one or more of the one or morethrough-silicon vias.
 18. The computing device of claim 13, wherein thefirst die is in direct contact with the die attach layer.
 19. Thecomputing device of claim 18, wherein the one or more build-up layerscover all of the second side of the reinforced plate.
 20. The computingdevice of claim 13, wherein the computing device is a mobile computingdevice further comprising: one or more of an antenna, a display, atouchscreen display, a touchscreen controller, a battery, an audiocodec, a video codec, a power amplifier, a global positioning system(GPS) device, a compass, a Geiger counter, an accelerometer, agyroscope, a speaker, or a camera coupled with the circuit board.